IS ELLEN TOO NICE?

Daytime television stardom can go on forever. Is that a blessing or a curse? Just a week after the announced departure of Kathy Lee Gifford from “Today,” the Netflix documentary “Ellen DeGeneres: Relatable” presents the affable afternoon host as she returns to stand-up.

Nobody has better cultivated a reputation for pleasantry than DeGeneres. But nice doesn’t cut it on the stage. How do you reconcile comedy’s requirement for truth-telling with her reputation for creating a daily haven for the feel-good?

Is DeGeneres “trapped” by her approachability?

And, as the documentary’s title hints, can an entertainer with a staggering income still “relate” to her audience?

Fabulously wealthy comedians like Jay Leno, Jerry Seinfeld and Tim Allen like to keep it “real” by talking about cars. What will DeGeneres do?

Decades back, viewers didn’t seem bothered by a performer with a “nice” reputation also appearing in darker fare. Fred MacMurray was one of television’s most beloved characters on “My Three Sons.” He parlayed that reputation into Disney hits “The Absent-Minded Professor” (8 p.m., TCM) and “Son of Flubber” (10 p.m.) from 1961 and ‘63. At the very same time, he starred as an adulterous heel in Billy Wilder’s 1960 classic “The Apartment.” He was a homicidal insurance agent in Wilder’s 1944 noir drama “Double Indemnity.”

At the time MacMurray appeared in “The Apartment,” he was considered the highest-paid star on television. He didn’t see straying from his “dad” image as a risk, and seemed to give his audience credit for realizing that he was acting.

— The final four compete on “The Voice” (8 p.m., NBC, TV-PG), followed by the finale (9 p.m.), the emergence of a winner and performances by Cher, Halsey, Kelly Clarkson, Jennifer Hudson, Miley Cyrus, Mark Ronson, John Legend and Esperanza Spalding.

— Chef Lidia Bastianich travels to small towns on “Lidia Celebrates America” (9 p.m., PBS, TV-G, check local listings) a celebration of regional food and local holiday traditions.

— Some might say that for New York City high school students, the world is their oyster. Some have dedicated their time to the unselfish act of saving shellfish.

“Take Back the Harbor” (8 p.m., Discovery) profiles the teens and teachers working to clean up the city’s harbor and working to restore the oyster reefs that used to be home to billions of bivalves. Along the way, we learn that restoring oysters will help clean the water of the bay since they filter countless gallons of pollutants.

— Kevin Frazier and Keltie Knight from “Entertainment Tonight” host “Greatest Holiday Commercials Countdown 2018” (8 p.m., CW, TV-PG), assigning one “great” sales pitch to each of the 12 days of Christmas. After that, the Holderness Family, of viral video fame, presides over the “Greatest Holiday Video Countdown” (8:30 p.m.), celebrating clips from both advertising agencies and amateur filmmakers.

— A sniper targets the greater New York area on “FBI” (9 p.m., CBS, r, TV-14). This series, produced by Dick Wolf, has been a hit for CBS. But its plots, depicting terror acts like bombings and snipers as common, daily or weekly occurrences, are absurd. And they must be seen as ginning up a climate of political paranoia completely divorced from reality.

TONIGHT’S OTHER HIGHLIGHTS

— Dan puts Becky on the payroll on “The Conners” (8 p.m., ABC, r, TV-14).

— Survivors of a 1964 Alaskan earthquake reconnect on “We’ll Meet Again” (8 p.m., PBS, TV-PG, check local listings).

— Lawrence leaves the seminary on “The Kids Are Alright” (8:30 p.m., ABC, r, TV-PG).

CULT CHOICE

— A ruthless dictator’s decline sparks a madcap scramble for succession in the 2017 satire “The Death of Stalin” (9 p.m., Sho 2), written and directed by Armando Iannucci (“Veep”). Banned in Russia.

SERIES NOTES

Gibbs gets custody of a terrorized girl on “NCIS” (8 p.m., CBS, r, TV-14) … Making adjustments on “Lethal Weapon” (8 p.m., Fox, r, TV-14).

Polaris’ baby suffers on “The Gifted” (9 p.m., Fox, r, TV-14) … Junior has other plans on “blackish” (9 p.m., ABC, r, TV-PG) … Mixed signals on “Splitting Up Together” (9:30 p.m., ABC, r, TV-14) … Pride has doubts about a case on “NCIS: New Orleans” (10 p.m., CBS, r, TV-14) … A 40-something divorcee joins the force on “The Rookie” (10 p.m., ABC, r, TV-14).

LATE NIGHT

Jimmy Fallon welcomes Michelle Obama and Lil Rel Howery on “The Tonight Show” (11:35 p.m., NBC) … Amy Adams, Stephan James, Anne-Marie and Richard Danielson visit “Late Night With Seth Meyers” (12:35 a.m., NBC) … Connie Britton, Gwen Stefani, Lin-Manuel Miranda and Emily Blunt appear on “The Late Late Show With James Corden” (12:35 a.m., CBS).